题目内容：

英语和介词有关选择
Besides being able to work for three days without drinking,camels can also live for a long time _____ small quantities of food.
这里为什么要用on?而不用by或in
its quite ___beyond___ me why such things have been allowed to happen.
这里的beyond的解释什么,还有什么类似的用法?
还有这个behind:
I'd love to.I can't wait to leave this place__behind__.
为什么用behind